Chain-stitch sewing-machine.



M. HEMLEB;

CHAIN STITCH $EWING MACHINE.

APPLICATION FILED NOV. 14, 1912.

Patented Au 18, 19m

2 SHEETS-SHEET 1.

' W/TNESSES: I %@7M, "J1 E v/zau ila lNVE/VTUR M. HBMLEB.

CHAIN STITCH SEWING MACHINE.

APPLICATION FILED NOV.14, 1912.

2 SHEETS-SHEET 2.

of the plural-armed MARTIN HEMLEB,

TENT @FFTCE OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

CHAIN-STITCH SEWING-MACHINE.

i ,iomoa.

Specification of Letters Patent.

Patented Aug. 1%., ilttDll il,

Application filed November 14, 1912. Serial No. 731,307.

To all wlmn'i it may concern Be it "known that I, MARTIN citizen ofthe United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Chain-Stitch Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an improvement in that class of stitch-forming mechanism adapted for production of a double-chainstitch seam and comprising-areciprocating needle, a thread-carrying looper cooperating therewith, and a spreader for distending loops of looper-thread for passage of the needle. Although in certain of its features for embodiment in other styles of machines, it is designed more particularly'for machines of the class represented in the United States patent to P. Diehl and \V. R. Houghton, No. 579,223, of March 23, 1897, in which the main-shaft is journaled within and longitudinally of the hollow bracket-arm and has a connection through a plural-armed rocker with the looper rock-shaft arranged beneath the bed-plate.

According to the present invention, in its preferred form, the main-shaft carries three separate actuating members connected respectively with the needle-bar journaled in the head of the bracket-arm, the looper rock-shaft mounted beneath the bed-plate, and the endwise reciprocating looper-bar disposed parallel with the looper rock-shaft and also mounted beneath the bed-plate.

HEMLEB, a

The needlcand looper-actuating members are preferably in the form of cranks, and the spreader actuating member that of an eccentric, but the crank and eccentric forms of those-actuating members are evidently full equivalents as regards the present invention, and are readily interchangeable.

The looper-actuating crank of the mainshaft has a pitman connection with one arm rocker whose other arm extends in the direction of the looper shaft carrying a crank-arm connected therewith by means of a pitman forming a shorttoggle comiection between the rocker and the looper v rock-shaft. The spreader-actuating eccentric has a pitman connection with the lateral arm of a belicrank mounted upon a fixed fulcrum transverse to the endwise reciprocating spreader-carrying bar-Which latter is pivotally connected with a depending arm of said bell-crank. By this construction, each ofthc operative elements of the stitch-formng mechanism has an operative connection independent of the others with a uniformly acting crank or eccentric upon the mainshaft of simple construction and so constructed and arranged as to impart easy movements to their respective stitch-forming elslnients, whereby high speeds are attaina e.

In the ,drawings,.]l*igure 1 is a front side elevation, partly in section, representing a machine embodying the present improvements, and Fig. 2 a bottom plan of the same. Fig. 8 is a transverse section through the hollow standard of the bracket-arm and viewed from the rearward end thereof to show the connections between the main-shaft and the parts beneath the bed-plate. Fig. 4: is an end View of the operative parts heneath the bed-plate, with the latter in transverse section. Fig. 5 is a perspective view of the stitch-forming elements detached from other parts of the machine.

The machine is shown constructed with the bed-plate 1 to which is secured the hollow standard 2 with tubular overhanging arm 3 in the head 4 of which is journaled the reciprocating needle-bar 5 carrying the multiple needle-clamp 6 in which are secured the eye-pointed needles 7 \Vithin and longitudinally of the bracket-arm is journaled the main-shaft 8 having upon its forward end the crank-plate 9 carrying the crank-pin 10 embraced by one end of the pitman 11 whose opposite end is connected with the collar 12Jfixed upon the needle-bar 5. The main-shaft has upon its rearward portion the looper actuating crank 13, the spreader-actuating crank-element in the form of an cecentric 14 and the intermediate feed-actuating eccentric'15, and is provided with the usual balance-wheel 16 with grooved beltpulley 17. The crank 13 is embraced by the strap 18 at the upper end of the pitmanrod 19 housed within the standard 2 with its apertured lower end embracing a stud 20 carried by the lateral arm 21 of a pluralarmed rocker having a hub portion 22 jour naled upon the center-screws 23 mounted in the depending lugs 24 of'the bed-plate and formed with an oppositely extending forked arm 25 embracing and pivotally connected by means of the pin 26 with the apertured llltt adja ent end of the link 527 whose apertured opposite end embraces a pin .28 carried by the crank-arm 29 whose hub is fixed upon the rearward end of the looper rock-shaft Ill mounted in depemling bearing lugs 32 of the btal'plalc. The rock-shaft 8 1 is disposed parallel with the main-shaft 8 and substan tiall in a plane embracing the needle-paths, and the hub 22 of. the plural-armed rocker is arranged parallel with such rock-shaft and with its crank-arm 2:) upon the side thercol nearest the rock-shaft.

Mount d upon the rock-shaft 31 is a hub 32} lixed thereon by means ot' the set-screw 3t whose conical point enters the V-shaped longitlnlinal groove 81. of the rock-shaft, and from this collar extend upwardly the shank portions of the loopers formed with the parallel blades 86 grooved and eye-pointed in a manner well known to receive the lower threads, the looper-points being directed oppositely to the direction of travel of the work or toward the front side of the machine as indicated in Fig. 4. Each looperblade is adapted to seize upper thread loops from its respective needle in the production of stitches.

represented in Fig. 8, the looper-actu- .ating crank 13 is in its highest position and the rocker-arm 25 in its extreme lower position below an imaginary line drawn from the axis of the rocker-hub 22 to the crankpin 28, and coi'isequently the toggle 25 27 is in extreme dwell-producing position bent slightly downward corresponding with the advance position of the looper (Fig. 1); As the crank 18 continues its rotation to lower position the rocker-arm 25 moves upwardly toward the bed-plate, carrying with it the link 27 which imparts to the crank-arm 29 a turning movement into a position at the side of the rock-shaft 31 adjacent the rockerhub 22 wherein the link 27 assumes an angular relation with the rocker-arm 25 approximating a right angle. In the reversal of movement of the rocker from this extreme position, therefore, a correspondingly quick movement is imparted to the IOCli-Sllflft 31 in contrast to that of the dwell-producing position represented in said figure.

The spreade'-actuating eccentric is embraced bythe strap 37 atthe upper end of a pitman-rod 38 depending within the standard 9 whose lower end is provided with a strap 89 embracing a ball-stud 40 upon the ateral arm 4-.1 of a bellcrank whose hub 42 is journaled upon the fulcrum-pin sustained by the standard transversely of the mainsha'tt, such bcllerank having a depending arm -l-t :lormed with a boss at its lower end having an elongated aperture entered by the pivotal pin to by which it is connected with the forked rearward end to of a coller 47 secured upon the rearward end of the endwise reciprocating spreader-bar 48 which is journaled in the bearing lugs 82 above and par; llel with the looper rm-k-shalt ill. The spreader-lair has lixcd upon its l'orward end the split collar it) provided with a laterally ott'set vertical seat 50 to which is secured by means of the fastening screw 51 the depending extension 5:2 oi the sprmnler-plate 53 having projecting from its rearward edge the spaced spreadcrJinmn-s -l-, each adapted to cooperate with one of the loopers 36 in spreading a lower thread for passage of the needle. The syneadeuplate 53 is provided at its forward end with the downwardly olfset extension 55 entering a suitable guideway formed between a depending seat 1 of the bedplate and a bearing plate 56 secured thereto by means of screws 57.

Depending from the bed-plate are spaced guide-eyes formed of the wires 58 secured in position by means of the screws 59 and between which reci n'ocates the take-up member (30 secured by screws 61 within a forked lug (32 of the split collar (33 adjustably secured upon the rock-shaft 31 by means of the clamp-screws 64. The takeup member is adapted to control the looper-threads leading from the source of supply through the guide-eyes 58 and. a guide-eye ()5 to the loopers 3G. I

Journaled beneath the bed-plate is the usual feed roek-shaft 66 having the upwardly extending arms 67 forming a yoke within which is pivoted the transverse member (38 of the feed-bar 69 carrying the feeddog 70 working through the usual aperture in the throat-plate 71. The feed rock-shaft 66 has a lateral arm 72 carrying a stud 73 embraced by the apertured lower end of the lin.kbar 745 whose offset upper end is pivotally connected by means of the pin 75 with the lug 7 6 upon the eccentric strap 77 embracing the feed-actuating eccentric 15, the bar 74 being fulcrumed intermediate its ends by means of a screw-stud 7 8 upon the upper end of a swinging link 79 whose lower end is pivotally mounted by means of the pin 80 upon a depending arm 81 of the feedregulating angle-lever mounted upon the fixed fulcrum 82 and having a lateral arm 83 by means of which the position of the supnnrting pin 80 is determined. At the opposite side and beneath the bed-plate is arranged the feed-lift IOCl Sl11fl1 84 carrying at its forward. end the lateral crank-arm 85 carrying the roller-stud 86 upon which rests the flat lower edge 69' of the feed-bar 69, the teed-lift rock-shaft having at its opposite end the lateral arm 87 forked to embrace the feed-lift cam 88 fixed upon the rocker-hub 22.

As will be seen from the foregoing description, the adaptation of the present improvements to the'structure represented in the Patent No. 579,223; before mentioned, involves a substantial reconstruction of the Cir machine, in the lateral and vertical position of the looper rock-shaft relatively to the needle paths to effect the proper handling of the needle-thread loops for prevention of penetration by the needles; the reversal of the looper-blades to extend oppositely to the direction of feed, acting in conjunction with the spreader and feeding mechanism in facilitating the distention of the lower-.

thread loops for passage of the needle so as to increase the certainty of cooperation of the stitch-forming elements; the provision of the spreader reciprocating crosswise of the looper-blades and introduced between the same and the throat-plate; and thereconstruction and relocation of certain elements of the dwell-producing looper-actuating means to accommodate the changes referred to and to admit of the employment of spreader-actuating means independently connected with the main-shaft and housed within the hollow bracket-arm standard.

According to the present improvement, the amplitude of rocking movements imparted to the looper rock-shaft 31 is considerably less than that of the earlier patent referred to, which has been made practicable in part by the relocation of such shaft, thereby permitting the use of a comparatively short looper-blade requiring the manipulation in the stitch-forming processes of a shorter than usual length of looperthread for control by auxiliary elements. The dwell of the loopers in their advance position provides ample time for effective engagement of the looper-thread by the spreader preparatory to descent of the needle-point through the loop thus formed and materially increases the efficiency of cooperation of these lower thread-handling elements as compared with uniformly moving elements of the same nature as heretofore employed.

In order to'provide the requisite compact ness of construction and arrangement of the parts to'insure quiet running, freedom from vibration and durability at the high speeds for which the present mechanism is designed, the looper-shaft is disposed as close as practicable to the bed-plate and the spreader-bar is mounted in the intervening space comparatively close to the top of the looper rock-shaft. In order to provide for such arrangement, the dwell-producing toggle device of the looper-actuating mechanism is disposed and is given a range of movement wholly below the spreader-bar, while the actuating mechanism of the latter is constructed in such manner as to be located entirely above the looper rock-shaft and its dwell-producing means. In other words, the spreader-bar is disposed intermediate the main-shaft and the looper rockshaft and has its, actuating means wholly upon the side thereof toward the mainshaft, while the dwell-producing means of the looper rock-shaft is disposed at the farther side of the spreader-bar from the main-shaft.

It will thus be seen that the needles, loopers and spreaders are all driven independently from uniformly acting cranks or eccentrics upon the main-shaft, and that the work-advancing movements of the feed-dog are also derived directly from still another eccentric upon the main-shaft, the rising and falling movements of the feed-dog being communicated from the intermediate rocking member through which operative movements are imparted to the looper. The entire mechanism is thus wholly free from any harsh movements and contains only a smoothly acting cam dog, whereby the machine is adapted to run freely at high speeds exceeding 3,000 stitches per minute with a minimum of noise and wear of the parts. All joints of the moving parts below the bed-plate liable to be cloggedmr otherwise impaired by accu mulation of dirt and other matter from the fabric under the stitching operation are thus located wholly beyond the outline of the aperture 89 in the bed-plate through which the stitching and feeding members act and are thus fully shielded by the bedplate from foreign matter. The type of looper mechanism employed adapts the machine for producing simultaneously parallel double-chainstitch seams having any desired spacing within a very wide range.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, the combination with the frame comprising a bed-plate and an overhanging bracket-arm formed with a hollow standard, a main-shaft journaled in the bracket-arm and carrying a looper-actuating member and a spreader-actuating eccentric, and a reciprocating needle operatively connected with the main-shaftinde pendently of said actuating member and eccentric, of a looper rock-shaft mounted beneath the bed-plate parallel with the mainshaft, an operative connection between said rock-shaft and looper-actuating member including an element extending through the bracket-arm standard, a thread-carrying looper mounted on said rock-shaft, an endwise reciprocating spreader-bar disposed parallel with said rock-shaft, an operative connection between the spreader-bar and said eccentric including an element also extending through the bracket-arm standard, and a spreader mounted upon said spreaderbar and adapted to distend loops of looperthread for passage of the needle.

for lifting the feed- 2. In a sewing machine, the combination v journaled in the bracket-arm, a reciprocating needle operatlvely connected with the main-shaft, and feeding mechanism, of

loopcr rock-shaft mounted beneath the bed-plate substantially within a plane embracing said needle, a thread-carrying loopcr mounted thereon with its point directed oppositely to the direction of feed, a reciprocating spreader-bar, a spreader mounted uponsaid spreader-bar and adapted to distend loops of looper-thread for passage of the needle, an operative connection between the mainshaft and the spreaderbar, and an operative connection between the main-shaft and the looper-shat't including neans for imparting to the latter to-and-fro movements with intermediate dwells of greater duration in the extreme advance position of the looper while coacting with the spreader than in the extreme retracted position thereof.

In a. sewing machine, the combination with the frame comprising a bed-plate and an overhanging bracket-arm, a main-shaft journaled in the bracket-arm and carrying a looper-aetuating member and a spreaderactuating eccentric, and a reciprocating needle operatively connected with the mainshalt, of a looper rock-shaft mounted beneath the bed-plateand operatively connected with said actuating member of the mainshaft, a thread-carrying looper mounted on said rock-shaft, an endwise reciprocating spreader-bar disposed parallel with said rock-shaft, a bellerank mounted upon a fixed fulcrum transverse to said spreader-bar and having an arm connected with the latter, a )itman-rod having at one end a strap embracing said actuating eccentric and having its other end connected with another arm of said bellcrank, and a spreader mounted upon said spreader-bar and adapted to distend loops of l-ooper-thread for passage of the needle.

4. In a sewing machine, the combination with a rotary main-shaft provided with a looper-actuating crank and a spreader-actuating eccentric, and a reciprocating. needle operatively connected with said shaft, of a looper rock-shaft provided With a crankarm, a thread-carrying looper mounted thereon and cooperating with the needle, a plural-armed rocker disposed parallel with said rock-shaft and having a crank-arm thereon upon the side adjacent the latter, a link connecting said crank-arms and having a range of movement permanently on the same side of said rocker, a pitman connection between said crank of the rotary shaft and another arm of said rocker, a

spreader coiipelating with said looper, and an operative connection between said spreader and the sprmulenactuating eccentric of the main shaft.

5. In a sewing machine, the combination with the frame comprisii'ig abed-plate and an overhanging brackets-arm, a main-shattjournaled in the bracket-arm, and a reciproeating needle operativel y connected with the main-shaft, of a looper rocl'trshat't mounted beneath the bed-plate paral el with the main-shaft, a thread-carrying loopermounted thereon, a reciprocating spreader-bar mounted intermediate the looper rock-shaft and the bed-plate, a spreader mounted upon the spreader-bar and cooperating with said looper,,an operative connection between the main-shaft and the spreader-bar disposed wholly upon the side of the spreader-bar nearest the mainshaft, and an operative connection between the main-shaft and the looper rock-shaft comprising a dwell-producing toggle device arranged beneath the bed-plate and having a range of movement permanently below the spreader-bar actuating means.

6. In a sewing machine, the combination with the frame comprising a bed-plate and an overhanging bracket-arm, a main-shaft journaled in the bracket-arm, a throat-plate sustained by the bed-plate, and a plurality of reciprocating needles operatively connectand operatively connected with the mainshaft, and a spreader-plate secured upon and sustained by the spreader-bar at one end and having the other end at the 'opposite side of said loopers slidingly journaled beneath the bed-plate and its intermediate portion upwardly offset and formed with a series of spreader-fingers movable intermediate the range of movement of said loopers and the throat-plate and adapted to cooperate with said loopefs.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

MARTIN HEMLEB.

Vitnesses: I

L. E. Firsonnn, I'IENRY A. KORNEMANN, Jr. 

